16641

16641 is a natural number that follows 16640 and precedes 16642. It is a perfect square, with the integer square root 129, since 129^2 = 16641.

Its prime factorization is 3^2 × 43^2, giving prime divisors 3 and 43. Consequently, 16641 = (3 × 43)^2 = 129^2. The positive divisors are 1, 3, 9, 43, 129, 387, 1849, 5547, and 16641.

In base 16, 16641 is written as 0x4101. The sum of its decimal digits is 18, and the number is divisible by 9 (16641 ÷ 9 = 1849).

As a square of a composite number, 16641 is an example of a square where the root is itself composite (129 = 3 × 43). It lies between the squares of 128 and 130: 128^2 = 16384 and 130^2 = 16900.